1. Field of the Invention
The present invention relates to a power module used in a motor control device.
2. Discussion of the Background
A conventional power module mounted on a motor control device such as an inverter or a servo amplifier is typically provided with a plurality of semiconductor devices (for example, six semiconductor chips and six freewheeling diodes) disposed on an insulated circuit board. As examples of such a semiconductor device, there has been known a so-called IGBT (Insulated Gate Bipolar Transistor) module having an IGBT therein, and an intelligent power module configured by an IGBT module with a gate drive circuit or a protection circuit. This type of a power module is disclosed in Japanese Unexamined Patent Application Publication No. 2005-123233. The Publication describes a cooling structure of a power module in which heat sinks are joined respectively to both sides of a semiconductor chip, and coolers are provided respectively over these heat sinks.